Patent GB-1014368-A (GB)
Title: Automatically actuated sewing machine
IPC: D05B65/00
Filed: 1964-09-03
Abstract: 1,014,368. Sewing machines. SINGER CO. Sept. 3, 1964 (Sept. 11, 1963], No. 36187/64. Heading D1G . Sewing apparatus comprises a sewing machine, a work support mounted for universal movement in a plane relative to the stitching print, a member provided with a pattern line, a tracer mechanism for generating a varying electrical control signal in response to the relative position of the tracer mechanism laterally of the pattern live, and means responsive to the control signal for effecting relative movement between the tracer mechanism and the pattern line in a path conforming to the pattern line and for simultaneously imparting corresponding movement to the work support. Feed by clamps, frames. Figs. 6, 5, 7. A wooden table top 1 is carried by legs 2 and supports the base 23 of a sewing machine 22. A heavy aluminium plate 3, spaced from table top 1 by longitudinal strips 4, carries bearing blocks 20 slidably supporting longitudinal rods 18 and 19. Blocks 17, rigid with rods 18,19, are tied together by plates 21 and are rigid with transverse rods 10, 13 and 14. Bearing blocks 11, slidable on rod 10, support a vertical plate 9. Vertical plates 7 and 8 are supported by I beams 12 rigid with bearing blocks 15, 16 slidable on rods 13 and 14 respectively. Plates 7, 8, 9 support an upper horizontal work-supporting plate 6. A removable work clamp is supported on a shoulder 183 provided at an opening 182'in plate 6, and is held down by a pair of clamp arms 184 which are pivoted to plate 6 and are connected by links 187 to the piston rods 188 of respective pneumatic jacks 189 supplied with air by ducts 190 from a manifold 63 via relevant ones of a series of solenoid values 64. A trip arm 192 actuates an interlocking switch 191, permitting starting of the machines only if the work clamp is correctly located. The work-supporting structure is driven by wheels 193, 198 engaging opposite sides of a plate 194 removable held in an opening in plate 6. Wheel 198 is journalled in the forked upper end of a spindle 201 which is journalled in plate 3 and is spring-biased upwardly. A lever 208 engaging the lower end of spindle 201 is adapted to shift the latter manually downwards. Wheel 193 is journalled in the forked lower end of a sleeve 215 journalled in a bridge plate 216 carried by uprights 218, 219 fixed to table top 1. A motor 220, rigid with sleeve 215, drives wheel 193 via gearing 223, 224, 226, 227. A tracing unit 230, Fig. 6, comprises a fixed lower portion 232 mounted in a bracket 233 depending from plate 216. Portion 232 contains lamps 234 for illuminating a pattern line provided on a plate 261 removably held in an opening in plate 6, and also contains a lens 235 for focusing the image of the pattern line. Unit 230 also comprises an upper portion 236 which is journalled in plate 216 and contains a vertical rod 238 pivoted intermediately at 239. The lower end of rod 238 carries a photocell 237 and the upper end carries a permanent magnet 240 co-operating with an electro-magnet 241 supplied with alternating current, whereby photo-cell 237 vibrates at the frequency of the current. A servomotor 242, mounted on plate 216, drives a gear 244 meshing with a gear 245 rigid with portion 236. Lens 235 focuses the image of the pattern line on photo-cell 237, and the arrangement is such that, while the vibration is centred on the pattern line, the alternating voltage generated by the photocell constitutes a pure sine wave. When the pattern line departs from said centred position, either the negative or the positive portion of the wave is reduced, and the servo-motor 231 responds to this change to turn the upper portion 236 for maintaining the pattern line centered. A pulley 246 on portion 236 is coupled by a belt 247 to a pulley 248 on sleeve 215 for turning the driving wheel 193 correspondingly, and sleeve 215 is coupled via belts 249,253 and a vertical shaft 251 to spindle 201 for turning wheel 198 correspondingly. A knob 255 on shaft 251 provides for manuals turning of the wheels 193, 198. Associated with unit 230 is a programming unit 256 which is carried by a bracket 257 and contains a lamp 258, a photocell 259 and a lens 260. Unit 230 senses a series of programming dots, provided adjacent the pattern line, to control the operation of the apparatus by actuating certain of the valves 64. Plate 6 is held stationary each time the needle decends by the energization of an electromagnet 264 which is rigid therewith and which cooperates with a steel plate 266 on plate 3. Plate 6 is also held stationary when the sewing machine is inoperative by the descent thereon of a presser foot 48. Driving, upper and lower shafts connecting. Figs.1, 5, 9, 12. The sewing machine 22 has a lower arm 25 journalling a shaft 37 and an upper arm 28 journalling a shaft 29.- A pulley 31 fast on shaft 29 is coupled by a belt 30 to a pulley 32 driven by a two-speed motor 34. Shaft 37 has a crank arm 38 carrying a pivoted block 39 slidably embraced by a fork member 40 pivoted at 41. A pitman 42 connects a crank pin 45 on shaft 29 with a pivot 43 on member 40, whereby rotation of shaft 29 causes oscillation of shaft 37. A stop arm 80, adapted to engage a stop shoulder on pulley 31, is carried by a bracket 81 pivoted on a pin 55. Bracket 81 is connected by a link 82 to a bell crank lever 83 pivoted at 84. Lever 83 is also connected by a link 85 to an inner lever arm86 rigid with the pivoted pin 55. An outer lever arm 87, rigid with pin 55, is connected by a link 88 to the piston rod 89 of a pneumatic jack 90 supplied with air by a duct 91,via a solenoid valve 64, for rocking bracket 81 to disengage arm 80 to start the machine. Bracket 81 is retained in the running position by engagement of a pawl 92 with a shoulder on lever 83. For stopping the machine, pawl 92 is disengaged from linear 83 by supplying air to a jack 94, via a valve 64, whereby the piston rod 95 of jack 94 engages a pin 96 on pawl 92. An arm 100, rigid with piston rod 89, actuates a switch 99 when bracket 81 is released to stop the machine, whereby the piston rod 57 of a pneumatic jack 58 rises to lower the presser foot 48. When jack 58 is operated to raise the presser foot, an arm 69 rigid with piston rod 57 actuates a switch 70 for initiating operation of jack 90 to start the machine. Presser bars lifting, needle guides. Figs. 1, 9, 12,18. A presser bar 46 is rigid with a bracket 47 carrying a presser foot 48 serving as a guide for the needle 36. Presser bar 46 is connected by a lost-motion linkage to one end of a shaft 49. A crank arm 52 on the other end of shaft 49 is connected by a link 53 to the inner end of a lever 54 which is pivoted intermediately on the pin 55. The outer end of lever 54 is connected by a link 56 to the piston rod 57 of jack 58. Air is supplied to the upper end of the latter, for raising the presser foot, by a duct 60, and to the lower end, for lowering the presser foot, by a duct 61, admission of air being controlled by respective solenoid valves 64. A pin 77 on bracket 47 engages a slot in the lower end of a link 76, the upper end of which is pivoted to the armature 75 of a solenoid 73, the latter being energized to raise the presser foot slightly at each stitch. A shaft 107 is oscillated by an arm 108 co-operating with a cam 110 rigid with arm 40, whereby each one of a pair of switches is actuated alternately once for each reciprocation of the needle bar to energize respectively solenoid 73 for raising the presser bar, and solenoid 264 for holding the work support. Thread cutters. Figs. 9, 14, 18. A cutter bar 113 is connected by a bracket 114 to the piston rod 115 of a pneumatic jack 116 and is slidable in a slot 117 provided in the latter. Jack 116 is pivoted about a stud 119 on a plate 121 fixed to the standard 26 of the sewing machine. A stud 122, upstanding from bar 113, passes through a cam slot 123 in a fixed block 124, slot 123 having a straight front portion 137, an inclined intermediate portion 138 and a straight rear portion 139. a fixed knife blade 125 is mounted at its rear end on a pin 126 on bar 113, and a lug 128 at the front end of blade 125 engages a groove 129 in bar 113. A movable knife blade 127 is pivoted on pin 126 between bar 113 and blade 125, and carries an upstanding stud engaged in a cam groove 136 in the lower surface of block 124. Groove 136 has an edge 140 parallel to the edges 137,138,139, and a straight edge 141 parallel to edge 137 and spaced from edge 140 at a distance greater than the diameter of stud 135. The front end of edge 140 has an inclined portion 142 and the rear end of edge 141 has an inclined portion 143. Jack 116 is supplied with air to move bar 113 forwardly by a duct 144 via a valve 64 controlled by a switch 72, Fig.12, which is actuated by an arm 71, rigid with piston rod 57, when the latter rises to lower the presser foot 48. Stud 135 then moves along edge 140, and a cutting edge on blade 127 is spaced from a cutting edge on blade 125 to receive the needle thread therebetween. When stud 135 engages edge 142, blade 127 is closed to sever the thread and to grip the thread end between blade 127 and bar 113. At the end of the forward stroke of bar 113, a flange 147 thereon actuates a switch 154 to exhaust duct 144, when low-pressure air permanently supplied to the front end of jack 116 by a duct 145 moves bar 113 rearwardly with pin 135 engaging edge 141 and the thread end clamped, until flange 147 engages an abutment 148 pivoted to the lowered piston rod 149 of a pneumatic jack 150, not shown, to prevent engagement of pin 135 with edge 143. After the insertion of a few stitches in a new seam, jack 150 is evacuated and rod 149 is raised by spring means to free detent 148 from flange 147. Bar 113 then couples its return stroke, whereby stud 135 engages edge 143 to open blade 127, and stud 122 engages edge 138 to swing the front end of bar 113 away from the presse